Bacillus Thuringiensis

cabbage looper :Variable results (poor to excellent);
especially useful on pests that have become resistant to
traditional chemical sprays

Newly hatched larvae of the cross-striped cabbageworm are gray
with small black tubercules and large round heads; mature larvae
are green to bluish gray with at least three distinct black bands
across each segment. Long dark hairs grow out of the black
tubercules, and the slender worms grow to 2/3 inch long. The
adult is a small pale yellow moth, with mottled brown patterns on
the forewings and partially transparent hindwings. See imported
cabbageworm, below.

The fat, smooth, pulpy cutworm [color] is as troublesome as it
is ugly. Of the many species, you are most likely to run into the
black, bronzed, and dingy cutworms. The black cutworm (or greasy
cutworm) is gray to almost black and has a broken yellow line
down the center of its back with a pale line to each side. It
grows to 1 1/2 inches or even longer and has a shiny, greasy
appearance. As its name suggests, the bronzed cutworm is bronze
in color and displays five pale lines from head to tail. It is a
pest in the northern states. A northern cousin is the granulate
cutworm, which has a rough, granulate-appearing skin and a dusty
brown color. It burrows very shallowly in the soil, often
exposing its back. The dingy cutworm, a northern species, is also
aptly named--it is a dull, dingy brown, and has a wide, pale
stripe running the length of its back, flanked by a thin dark
stripe on each side. It sometimes crawls up the stems of plants
to feed.

Although the larva of the diamondback moth is a relatively
minor pest, it at times can cause considerable damage to the
cabbage family by eating small holes in the outer leaves. These
caterpillars grow only to 1/3 inch long, are greenish yellow with
black hairs, and when disturbed will wriggle and drop to the
ground. The adult is a gray to brown, small (3/4-inch-across}
moth, with fringed back wings; when the moth is at rest, look for
the diamond on its folded wings. See BACILLUS THURINGIENSIS for
an effective biological control. Southernwood is an herbal
repellent.

The fall armyworm [color] is so called because it travels in
veritable insect armies to consume everything in its path and
because it does not appear until fall in the North. The larvae
vary greatly in color, from light tan to green to almost black,
and have three yellowish white hairlines down the back from head
to tail. On each side is a dark stripe paralleled below by a wavy
yellow one splotched with red. The head is marked with a
prominent white V or Y. They eat leaves, stems, and buds of
plants. Naturally occurring enemies include parasitic ichneumon
wasps and, of the braconid wasps, Chelonus texanus, Meteorus
laphygmae, and species of Apanteles. Other beneficial insects are
tachinid flies, ground beetles, and the commercially available
nematode Neoaplectana carpocapsae. For other control measures,
see armyworm under CORN.

The very visible harlequin bug [color] is black with brilliant
orange to red markings. It is shield-shaped, flat, and 3/8 inch
long. Although attractive to the eye, the bug has a disagreeable
odor at all stages. It is among the most important pests of the
cabbage family in the United States, as local infestations often
destroy whole crops, especially in the South. The bugs spend the
winter around old plants and other trash that accumulates in the
garden. In early spring they lay their eggs on the undersides of
early blooming plants. The distinctive eggs are easy to spot
--they look like small white pegs with black loops, standing on
end, lined in two neat rows. Look for and destroy these eggs
whenever possible; if allowed to hatch, the immature nymphs drain
the juices out of the plants, causing them to wilt, turn brown,
and die.

Plant a trap crop of turnips or mustard greens near or around
the cabbage patch to lure away harlequin bugs. Patrol the trap
area, remove the bugs, and drop them into a jar of water topped
with kerosene. Insecticidal soap sprays give good control.
Sabadilla and pyrethrum, two plant*derived insecticides, are
effective.

The bright green, velvety smooth imported cabbageworm [color;
see Cabbageworm] is covered with close-set hairs and grows to one
inch or longer. A yellow green stripe runs down its back. The
worm is found in every state.

No member of the cabbage family is safe from its appetite,
although sea kale is rarely bothered. It eats huge, ragged holes
in leaves and spots the feeding area with bits of excrement. It
also bores into heads of cabbage. The adult is the well-known
white cabbage butterfly, whose white to pale yellow wings have
either three or four black spots; the tips of the front wings are
grayish. In the early spring, these butterflies may be seen
depositing their lemon yellow, bullet-shaped eggs at the base of
leaves. The eggs usually take from four to eight days to hatch,
depending on temperatures. They turn straw yellow just before
hatching.

The cabbageworm may be attracted to your land by weeds of the
cabbage family--wild radish, wild mustard, and wintercress. These
wild plants should be cleared from the vicinity of the vegetable
garden. Cole plants can be protected by a border of plants that
are shunned by the cabbage butterfly; these include onion,
garlic, tomato, sage, tansy, mint, southernwood, nasturtium,
hemp, hyssop, and rosemary.

Insect predators and parasites claim a lot of these pests, but
don't expect too much help from the birds around your garden;
because of toxic body fluids, the caterpillars aren't favorite
foods. Brownheaded cowbirds, song sparrows, and redwing
blackbirds eat some cabbageworms. Yellow jackets have been found
to thrive on these pests, and their presence should not be
discouraged. The braconid wasps Macrocen trus ancylivorus,
Apanteles glomeratus, and Agathis diverse are extremely helpful
control agents. They are small insects with short abdomens, and
rank as important parasites of aphids too. Numbers of dead aphids
about the garden with a round hole in the back testify to the
presence of these wasps. You can encourage M. ancylivorus by
planting strawberries near the garden, as it also feeds on the
strawberry leafroller, and by avoiding poison sprays. Another
friend, the trichogramma wasp, is a commercially available
parasite that attacks many worms of the Lepidoptera order,
including the cabbageworm. This wasp lays its eggs inside the
eggs of harmful insects by the use of a pointed egg-laying
apparatus. When the trichogramma egg hatches, the young parasite
proceeds to eat out the contents of the egg in which it lives,
causing the egg to blacken and preventing one more insect from
harming the garden. See TRICHOGRAMMA. Bacillus thuringiensis was
found to be far more effective than Sevin, a popular chemical
insecticide. Nuclear polyhedrosis virus also works to control the
larvae. The two pathogens can be sprayed at the same time for
maximum effect; see individual entries for each.

Homemade remedies may help. Simply spoon a little sour milk
into the center of each cabbage, say some gardeners, and the
heads will be trouble-free. But a test at the University of
Illinois showed that sour milk actually increases damage. A
repellent drench can be made by blending, in a mixer, spearmint,
green onion tops, garlic, horseradish root and leaves, hot red
peppers, peppercorns, and water. Add some pure soap, dilute, and
pour on each plant. Or make a powder of to cup of salt and one
cup of flour and shake it on the cabbages while dew is still on
the leaves. Sprinkle up to an ounce on the worst heads. When the
worms eat the mixture they bloat up and fall off dead. These two
ingredients can also be mixed with water to produce a safe spray.
Other gardeners get by with an occasional sprinkle from a
saltshaker. This should be done right after rain or when there is
dew on the plants. A sprinkling of straight rye flour (it's
stickier than whole wheat} will gum up the worms if the plants
are wet.

Protective canopies of lightweight polyethylene or nylon
netting can keep egg-laying cabbageworm moths from tender young
broccoli and cabbage plants. The netting is easy to stretch over
rows and is available from most garden supply stores and
mail-order houses. Simple frames of wood can be constructed to
support the netting. Although the netting will keep butterflies
from laying eggs on the plants, the pupae spend the winter
underground and often surface around the plants to cause trouble.
Till the soil several times in fall and early spring to expose
these pupae to the air so that they will dry up and die. You
should also relocate the patch to keep from perpetuating problems
with these latent underground pests. Some gardeners trap cabbage
loopers in stems, and the outer layers of leaves of cabbage
heads; they also enjoy collards. In the Northeast and Utah, the
larva of the purplebacked cabbage moth feeds from inside a silken
web. The zebra caterpillar is a velvety black with two bright
yellow stripes on each side and many thin, yellow transverse
lines. The southern cabbageworm looks similar to the imported
cabbageworm, but its appearance is distinguished by alternating
longitudinal stripes of bright yellow and dark greenish purple,
and it is scattered with black spots. The yellow woollybear
caterpillar is bright yellow and very hairy.

You may find any of several species of the nocturnal mole
cricket eating or flying about the garden at night or on very
cloudy days. They may be drawn to lights near the garden. The
northern and southern mole crickets are the species of most
concern to gardeners. They are large ( 11/4 inches long) and have
sturdy shovel-like forelegs that are adapted for digging into the
soil. The northern species is brownish gray above and paler
underneath, while the southern is a pinkish buff. Both species
are a problem only in the South and are at their worst in warm,
moist weather. Their tunnel cuts off the roots of seedlings, and
some young plants may be totally uprooted. Moles may also chew
off stems at the soil surface and pull the plants down into their
tunnels. See GRASSHOPPER.

The seedcorn maggot also attacks young crucifers, especially
cabbage and radishes. They are dirty-yellowish-white, l/4 inch
long, and have pointed head finds. For control measures, see
cabbage maggots, above.

Thy malodorous green stink bug [color] is smooth oval, bright
green, and about ah inch long. They are occasional pests of
cabbage and mustard, piercing stems and leaves to suck sap and
leaving tiny holes in the center of surround ing cloudy spots.
Small plants are stunted and distorted. Control by keeping down
weeds. Spray with soapy water. See SNAPDRAGON.

The vegetable weevil [color] is a dull buff color with a pale
V on its wing covers. The head has a short, broad snout. They are
3/8inch long, rarely fly, and attack cabbage, carrot,
cauliflower, mustard, radish, and Swiss chard. The adults devour
foliage at night and hide close to the ground during the day. The
green or creamcolored larvae are also destructive. sheets of
colored plastic that are folded twice and placed on the ground
every three days or so. The captives are then shaken into a
bucket of water.

Not all of the many worm pests of the cabbage and its
relatives can be discussed here, but a few of occasional or
regional importance deserve mention. Control as for the imported
cabbageworm, above. The yellow, purple-striped gulf white
cabbageworm feeds on the leaves,